Envelope



Aug. 23, 1938.15 M, VOGEL 2,128,196

ENVELOPE Filed Aug. 5, 1935 INVENTVOR P QAX VUEEL. W ru /7% ATTORN EY Patented Aug. 23, 1938 UNITED STATES ENVELOPE.

Max Vogel,

Frankfort-on-the-Main,

G ermany Application August 5, 1935, Serial No. 34,798 In Great Britain February 2, 1935 2" Claims.

The present invention relates to an improvement in envelopes, particularly of the type in which the closure is effected by means of superposed dry adhesive surfaces, an object being to provide means which will be invisible or practically so, when the envelopes have been closed in the regular way, but which will clearly disclose any attempt to open the envelope in an unauthorized manner and then reclose it.

According to the invention at least the closing flap having the dry adhesive surface at one side is provided with incisions which are kept closed by the entrance therein of the adhesive substance and are thus invisible or practically so. The incisions may be in the form of short lines, curves, figures, or letters, preferably at the free edge of the flap or within the dry adhesive surface. For further securing the envelope the side flaps may also show punchings, for instance arcuate incisions.

With the above and other objects in view embodiments of the invention are shown in the accompanying drawing, and these embodiments will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out in the claims.

In the drawing- Fig. 1 shows an open envelope with incisions in the form of a row of parallel short lines at the edge of the closing flap. I

Fig. 2 shows an envelope with incisions in the form of an interrupted row of parallel short lines in the closing flap.

Figs. 3 and 4 show incisions in the form of curves in both dry adhesive strips, Fig. 3 show ing them in line and Fig. 4 showing them staggered.

Fig. 5 shows incisions in the form of curves on the fia'p, and

Fig. 6 shows incisions in the form of letters.

Referring to the drawing, the envelope H is provided with a dry adhesive strip l2 applied to the inner surface of the flap and with a dry adhesive strip l3 applied to the upper marginal portion of the back sheet of the envelope in position to be superimposed by the strip I2 when the flap is closed. The dry adhesive is generally latex which is applied in a suitable manner and which, when in contact with other bodies, will not adhere, but when in contact with another similar adhesive surface is highly adhesive.

An envelope closed by means of this dry adhesive surface may be opened by using some skill, without the paper surface being destroyed. It is thus not necessarily apparent in the case of a reclosed envelope, whether it has been opened or not.

The invention makes it possible to provide securing means in such a manner that, when the envelope is opened by separating the dry adhesive surfaces 2. portion of the envelope will be destroyed, so that it will be at once apparent from Y the reclosed envelope that it has already been closed, opened and reclosed. The safety arrangement which according to the invention consists of incisions in one or both dry adhesive surfaces is so constituted that it will not or will only barely be recognizable as such.

This result is due to the fact that the latex penetrates into the gaps formed by the incisions and closes them, so that they are invisible or practically so.

The incisions may be arranged either at the edge or spaced from the edge within the dry adhesive surface. Either one or both of the dry adhesive surfaces may be provided with them and in the latter case they may be so arranged that when the envelope is in the closed state, they either coincide with one another or are offset with respect to one another. Should the envelope be opened by an unauthorized person, there will be superposed weakened places in the two paper sheets having the dry adhesive surfaces, which will with certainty be destroyed.

In the arrangement according to Fig. 1 the incisions are provided in the form of a row of parallel short lines [4 at the free edge of the closure flap, while Fig. 2 shows the arrangement of groups of parallel short lines in the middle part of the closure fiap. In the examples shown in Figs. 3 and 4 the incisions I6, I! and I8, 19 are hookshapcd and lie, when the envelope is in the closed state, one on the other in the opposite direction, so that very much weakened places in the envelope result, which on the superposed adhesive strips being separated, will with certainty become torn. In the example shown in Fig. 4 the hook-shaped incisions l8, H! are arranged in staggered relation to one another, so that in this case as well, when the envelope is in the closed state, besides the weakening of the cross-sections through the hook-shaped incisions themselves. there are further weakening lines between the incisions which are oifset with respect to one another when the envelope is in the closed state. 50 In Fig. 5 the incisions 20 have the form of an undulating line, while in Fig. 6 the incisions 2| are in the form of letters.

For providing further proof of tampering the side flaps 24, Fig. 1 may for instance have 55 arcuate incisions 26, 21 which, on the side flaps being opened, become torn.

I have illustrated and described preferred and satisfactory embodiments of my invention, but it will be obvious that changes may be made therein, within the spirit and scope thereof, as defined in the appended claims.

Having thus described my invention what I claim and desire to secure by Letters Patent is:

1. In an envelope, means for securing the closure, effected by means of superimposed dry adhesive surfaces, said surfaces each comprising an elastic substance, the substance upon one surface adapted to adhere firmly with the substance upon the other surface without moistening when said surfaces are juxtaposed, at least one of said dry adhesive surfaces being provided with incisions which prior to juxtaposition of said surfaces are kept closed by the adhesive substance forming an elastic bridge between the edges of said incisions whereby upon separation said edges are brought back together by said elastic bridge and are additionally held closed by joining of the other adhesive surface with the adhesive bridging said incisions upon said juxtaposition.

2. In an envelope, means for securing the 010 sure, eflected by means of superimposed dry adhesive surfaces. said surfaces each comprising an elastic substance, the substance upon one surface adapted to adhere firmly with the substance upon the other surface without moistening when said surfaces are juxtaposed, at least one of said dry adhesive surfaces being provided with incisions at its edge which prior to juxtaposition of said surfaces are kept closed by the adhesive substance forming an elastic bridge between the edges of said incisions whereby upon separation said edges are brought back together by said elastic bridge and are additionally held closed by joining of the other adhesive surface with the adhesive bridging said incisions upon said juxtaposition.

MAX VOGEL. 

